apina.biz video to gif userscript

gistfile1.txt

// ==UserScript==
// @name        Apina.biz video2gif
// @description Replace apina.biz videos with gif
// @namespace   bionik
// @include     https://apina.biz/*
// @version     1
// @grant       none
// ==/UserScript==

var videos = document.querySelectorAll('video.gif');
for(var i = 0; i < videos.length; i++){
  var video = videos[i];
  var video_source = video.querySelector('source');
  var video_src = video_source.src;
  
  var img = document.createElement('img');
  
  var img_src = video_src;
  img_src = img_src.replace(".webm", ".gif");
  img_src = img_src.replace(".mp4", ".gif");
  img.src = img_src;
  
  img.width = video.width;
  img.height = video.height;
  
  video.parentNode.replaceChild(img, video);
}